The Mouse Genetic Core (Core A) will support the work of the Program Project Grant (PPG) by providing BAG transgenic mouse strains to Projects 2 and S.The Core will also as integrate recombineering technology with BAG transgenic production based upon the results obtained in Projects 1 and in support of Project 2 and 3. The Core will further determine expression levels of isoforms of mouse SLAM-Family genes and provide these data to Project 1, 2 and 3. In addition, the Genetic Core will serve as a repository for all newly developed mouse strains and distribute breeder pairs of these mice to the Projects and the scientific community, as needed. Specific Aim #1: To generate BAC-based transgenic mouse strains which will be bred with the C57BL/6 mouse that lacks the whole SLAM-locus and with the CD48 and Ly108 C57BL/6 mice. Specific Aim #2:To examine the expression of splice variants of mouse SLAM family members in NZM2410, NZM2328 and 129Sv/C57BL/6 congenic 86-100cM mice. Specific Aim #3: Maintain transgenic and knockout mouse strains used by Projects 2 and 3.